Scientists discovered something surprising about steroids like dexamethasone, which doctors give to brain tumor patients to reduce swelling. When these steroids are used, they change how brain tumors use certain nutrients, particularly something called nicotinamide. The researchers found that brain tumors accumulate much more of a nicotinamide product than normal brain tissue. This discovery led them to develop a new imaging test to spot these tumors and a potential new treatment combining steroids with a special diet low in methionine. The findings could help doctors better detect and treat glioblastoma, a serious type of brain cancer.

The Quick Take

  • What they studied: How steroid medications change the way brain tumor cells use nutrients, and whether this change could help doctors find and treat tumors better
  • Who participated: The study included laboratory experiments with glioblastoma (brain tumor) cells, patient samples from people with glioblastoma, and animal models with brain tumors
  • Key finding: When steroids are given, brain tumors accumulate about 7 times more of a substance called N1-methylnicotinamide compared to healthy brain tissue nearby, making tumors easier to spot and potentially more vulnerable to treatment
  • What it means for you: If confirmed in larger studies, this could lead to better ways to detect brain tumors early using special imaging scans and new treatment options combining steroids with dietary changes. However, this research is still in early stages and more testing is needed before it becomes available to patients

The Research Details

The researchers used multiple approaches to understand how steroids affect brain tumor metabolism. First, they screened tumor cells in the lab treated with dexamethasone (a common steroid) to see which nutrients changed. They then used advanced techniques to track how nutrients move through tumor cells from actual patients. They also studied the process in mouse models with brain tumors to confirm their findings worked in living organisms. Finally, they tested whether combining steroid treatment with a low-methionine diet (a nutrient found in many foods) could harm tumor growth.

This multi-layered approach allowed the scientists to move from basic laboratory observations to testing ideas in living systems, which is important for developing treatments that might work in humans. The use of patient samples was particularly valuable because it showed the findings weren’t just laboratory artifacts but reflected what actually happens in real tumors.

Understanding how steroids change tumor metabolism is important because steroids are already widely used in brain tumor patients. By discovering these changes, researchers can repurpose existing medications in new ways and develop better diagnostic tools. The tumor-specific nature of these changes (happening in tumors but not healthy brain) is especially valuable because it means any new treatment could target cancer cells while sparing normal tissue.

This research combines laboratory studies, patient samples, and animal models, which strengthens confidence in the findings. The use of stable isotope tracking (a precise method to follow nutrients through cells) adds scientific rigor. However, the study hasn’t yet been tested in human clinical trials, so results should be considered promising but preliminary. The research was published in Science Advances, a respected scientific journal, which indicates it passed peer review by other experts

What the Results Show

The main discovery was that when dexamethasone (a steroid) is given to glioblastoma cells, it triggers a specific enzyme called NNMT to become more active. This enzyme converts nicotinamide (a B vitamin-related nutrient) into N1-methylnicotinamide instead of NAD+, another important molecule. In patient tumor samples, this conversion happened at much higher rates than expected—nicotinamide was being turned into N1-methylnicotinamide about 7 times more than into NAD+.

When researchers looked at actual tumor tissue from patients, they found N1-methylnicotinamide accumulated to levels about 7 times higher in the tumor compared to surrounding healthy brain tissue. This dramatic difference is significant because it means tumors have a unique metabolic signature that could be used to identify them.

The researchers then developed a new imaging technique using a radioactive form of nicotinamide that can be detected with PET scans (a type of medical imaging). This approach could potentially help doctors visualize tumors more clearly and monitor how they respond to treatment.

An important secondary finding was that combining the steroid-induced metabolic changes with a methionine-restricted diet appeared harmful to tumor growth. Methionine is an amino acid (building block of protein) found in many foods. When tumors were forced to process nicotinamide differently by steroids and also had limited methionine available, this combination seemed to damage the cancer cells. This suggests a potential new treatment strategy combining existing steroids with dietary modification, though this needs much more testing

Previous research showed that steroids help reduce brain swelling around tumors, but scientists didn’t fully understand how steroids affected tumor cell metabolism itself. This study fills that gap by showing steroids don’t just reduce inflammation—they actively change how tumor cells process nutrients. The discovery of NNMT’s role in glioblastoma is relatively new to the field and opens up possibilities that weren’t previously considered. The imaging approach using nicotinamide is novel and builds on earlier work showing that tracking nutrient metabolism can help identify cancer

This research has several important limitations. Most experiments were done in laboratory cells or animal models, not in human patients, so results may not translate directly to clinical use. The study didn’t test the methionine-restricted diet approach in animals or humans yet, so its real-world effectiveness is unknown. The sample size for patient studies wasn’t clearly specified, which makes it harder to assess how representative the findings are. Additionally, the research doesn’t yet show whether the new imaging approach works better than existing methods for detecting brain tumors. Long-term safety and effectiveness data in humans is completely absent at this stage

The Bottom Line

Based on this research alone, no changes to current glioblastoma treatment are recommended yet (confidence level: low to moderate). The findings are promising enough to warrant further clinical testing, but they’re not ready for routine use. Patients currently taking steroids for brain tumors should continue their prescribed treatment as directed by their doctors. The methionine-restricted diet approach should not be attempted without medical supervision, as it could interfere with nutrition and other treatments. Doctors may want to watch for future developments in NNMT-targeted therapies and nicotinamide-based imaging

This research is most relevant to people with glioblastoma and their doctors, as it could eventually lead to better detection and treatment options. Researchers studying brain tumors and metabolism should pay attention to these findings. People taking steroids for other conditions don’t need to change anything based on this research. Family members of glioblastoma patients may find hope in these potential new approaches, though realistic timelines for availability should be understood

If this research leads to clinical trials, it typically takes 5-10 years for new cancer treatments to move from laboratory discovery to patient availability. The imaging approach might be tested in clinical settings sooner (2-5 years) since it builds on existing PET technology. The methionine-restricted diet combination would need careful testing for safety and effectiveness before any recommendation. Patients shouldn’t expect these approaches to be available immediately but can discuss them with their oncologists as emerging possibilities

Want to Apply This Research?

  • For patients currently in clinical trials or monitoring for glioblastoma: track steroid doses, timing, and any dietary modifications alongside symptom changes and imaging results. Record dates of PET scans if available and note any changes in tumor markers or neurological symptoms
  • Users could use the app to log steroid medication adherence and timing, maintain a food diary if exploring methionine content (with doctor guidance), and track symptom patterns like headaches, swelling, or cognitive changes that might correlate with treatment adjustments
  • Establish a long-term tracking system that correlates steroid use with symptom patterns and imaging results. Set reminders for medication timing and medical appointments. Create a symptom log to identify patterns that could inform discussions with healthcare providers about treatment effectiveness and potential new approaches as they become available

This research describes early-stage laboratory and animal studies that have not yet been tested in human clinical trials. The findings are promising but preliminary and should not be used to guide treatment decisions. Anyone with glioblastoma or a family member affected by this disease should discuss these emerging approaches with their oncologist or neurologist, who can provide personalized medical advice based on the patient’s specific situation. Do not attempt dietary modifications or changes to steroid use without explicit medical supervision. This summary is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare professionals before making any changes to cancer treatment or management strategies.